This invention pertains generally to television displays and more particularly to a system and method for aligning a television display to eliminate aberrations in the path of a beam forming the picture.
In television displays of the type commonly utilized in television receivers and monitors, the deflection of a cathode ray tube beam is controlled by ramp signals which are amplified and applied to the windings of a deflection yoke associated with the CRT. Even though the ramp signals may be substantially linear, non-linearities in the amplifier, yoke or CRT can produce visible non-linearities or aberrations in the path of the beam on the face of the CRT.
Heretofore, there have attempts to eliminate such non-linearities and aberrations by the use of permanent magnets positioned on or near the neck of the CRT. These magnets are positioned by hand, and they usually require manual adjustment. There have been other attempts to eliminate the non-linearities or aberrations by applying periodic correction signals to the scanning circuits. These signals are adjusted manually, and they generally do not eliminate all of the non-linearities and aberrations. These manual techniques are time consuming and expensive in a production environment, and they seldom provide completely satisfactory results.